Cooper and British model Suki Waterhouse, his girlfriend of nine months, stepped out for their first joint appearance last night at the New York premiere for Cooper's new movie, American Hustle. They got together shortly after Cooper and ex-girlfriend Zoë Saldana, who, just confirmed her recent marriage to Marco Perego, split. Adorably, they seemed to coordinate their outfits; Cooper looked dashing as always in a gray suit and black tie, while Waterhouse donned a gray turtleneck dress.

The pair sat together and munched on chocolate covered strawberries during the after party at Cipriani. "Guests were greeted with cocktails before entering the massive space, which was decked out 70s style complete with sparkling disco balls," a source told Us Weekly of the party. "Cooper posed with fans for photos, and later caught up over dinner [with Waterhouse.]"

Their night out a deux was a noticeable change from their casual outings together in Paris, Hawaii, and other far-flung locales. Despite their age difference (Cooper is 38, and Waterhouse is 21), their future plans align quite nicely. Cooper has been vocal about his commitment to family (he does still live with his mother, after all), and Waterhouse is preternaturally in agreement.

"I really like the idea of having kids in not too long," she said in the January issue of ELLE UK. "Not, like, now. And not next year. But in not too long."

The vivacious model also got somewhat bashful when the topic of Cooper came up. "I don't talk about my boyfriend because it's boring. At least, that's what I decided to tell you when you asked," she said. "I do think whatever I say will sound weird. But the truth is, if I start talking about him, I probably won't be able to stop. And I don't really want to talk about him, you know?"

It sounds like she's clamming up so she doesn't gush about her boyfriend. That, plus her premiere attendance, makes us think an engagement might not be too far off for this comely couple. Here's hoping!